Conventionally, a pump to be used in an aquatic application such as a pool or a spa is operable at a finite number of predetermined speed settings (e.g., typically high and low settings). Typically, these speed settings correspond to the range of pumping demands of the pool or spa at the time of installation. Factors such as the volumetric flow rate of water to be pumped, the total head pressure required to adequately pump the volume of water, and other operational parameters determine the size of the pump and the proper speed settings for pump operation. Once the pump is installed, the speed settings typically are not readily changed to accommodate changes in the aquatic application conditions and/or pumping demands.
Generally, pumps of this type are often operated in a non-supervised manner. However, a number of problems can develop in the aquatic application that can pose a risk to damage of the pump and/or even injury to a user (i.e., a swimmer) of the aquatic application. Examples of these problems can include a deadhead condition and an entrapment condition. In one example, a deadhead condition can be caused by an obstruction or the like in the plumbing downstream from the pump. The obstruction can be caused by various reasons, such as sedimentary build-up that occurs over time, a foreign object that is lodged in the plumbing, or a valve that has been inadvertently closed. The obstruction can cause damage to the pumping system, such as by a “water hammer” effect and/or by excessive loading of the pumping system. In another example, entrapment can occur when part of a user's body becomes attached to a suction drain (e.g., pool drains, skimmers, equalizer fittings, vacuum fittings and/or intakes for water features, such a fountains, slides or the like) because of the powerful suction of the pumping system. Though most pools and spas include suction drain grates, the grates can be loose, missing, and/or damaged over time. Thus, when a user stands or sits on the loose, missing or damaged drain grate, the suction from the pumping system can hold the user underwater and can cause drowning or other injuries.
Accordingly, it would be beneficial to provide a pump that could be readily and easily adapted to respond to a deadhead and/or entrapment condition to protect the users and/or the pumping system. Further, the pumping system should be responsive to a change of conditions and/or user input instructions.